[epiphone3]

I am looking for our true tech gurus to shine here.

I am changing my engine oil once my break-in is done (only about 750km left) and I was thinking about doing the manual transmission oil and the differential oil as well.

Any downsides to doing the manual transmission oil, other than cost?

Any downsides to doing differential oil? I have heard that completely bleeding the differential in the E90 is not a good idea due to its design... is this true?

Any other thoughts? I think it is cheap insurance and I am trying to get good, researched/proven thoughts from this forum.